As a species, we’ve gained an impressive degree of influence over our environment by deliberately simplifying ecosystems so they will support more humans, but fewer other species. Our principal strategy in this project has been agriculture—primarily a form of agriculture that focuses on a few annual grain crops. We’ve commandeered up to 50 percent of the primary biological productivity of our planet, mostly through farming and forestry. Doing this has had overwhelmingly negative impacts on non-domesticated plants and animals. The subsequent loss of biodiversity is increasingly compromising humanity’s prospects, because we depend upon countless ecosystem services (such as pollination and oxygen regeneration)—services we do not organize or control, and for which we do not pay.
The essence of our problem is this: the side effects of our growth binge are compounding rapidly and threaten a crisis in which the artificial support systems we’ve built over past decades (food, transport, and financial systems, among others)—as well as nature’s wild systems, on which we still also depend—could all crash more or less simultaneously.
~Richard Heinberg
http://www.postcarbon.org/the-anthropocene-its-not-all-about-us/